Remote controlling apparatus



lApril 16, 1940.

L.. V. LEWIS REMOTE CONTROLLING APPARATUS Original Filed July 9, 1928 4 sheets-sheet 1 April 16, 1940.

L. v. LEWIS 2,197,130

REMOTE CONTROLLING APPARATUS Original Filed July 9, 1928 4 Sheets-Sheet 2 oy09 @V0 Pay INVENTOR;

Fly. 2.

16, 1940. l.. v. I Ewls 2,197,130

REMOTE CONTROLLING APPARATUS Original Filed July 9, 1928 4 Sheets-Sheet 3 15 lNvENToR:

31 K La ms,

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REMOTE CONTROLLING APPARTUS v Original Filed July 9, 1928I 4 Sheets-Sheet 4 Pate,.aApr.`16,194o N2,197,130

-UNiTED`-sTATx3s PATENT? omer,

to The Union Switch and SignalnGompany, Swissvale, Pa., a corporation of, lennsylvania Application July 9, 192s, serialize.y 291,465'

. Renewed November' 1'4, 1931 135 Claims. Cl. 246-5) My invention relates to remote controlling apmined bythe positions 'of the operators levers at paratus, and particularly to vapparatus ofA thev the .office or the conditi'onsof the devices in the vtype adapted for controlling traflic governing de-y eld and parts" (station selecting) being detery vices, such as railway switches' and signals, from mined by` apparatus individual to the group of 5 a'remote point, such for example,jas a train dis-v levers orv group of devices With which the code i patchers office, and for also indicating the condioriginates.`

tion of suchy devices at said office.v Each receivingzequipment includes. apparatus Suchs'ystemsare customarily identified in the selectively responsive to the function selecting art as centralized traic control systems;` parts of the code to govern the plurality of de- 'In systems of this` character the traffic govvices or indicators associated with that receiver. 1J erning devices are grouped at field Istations dis- Therefore,r by my invention an operatorat the tributed along the right of way, and these deofce by merely transmitting a single code will lvices are lconveniently controlled by manually select any station and control a complete route operable leversfunder the control of `theopei'ator thereat by positioning a. switch and clearing a l inthe oice. These levers may be divided-into signal .vg'overningjtrafc movements over the 15 groups or "panels corresponding -to the eld stasvvitch; and, conversely, a single code individual tions With 'which' they are associated, and each to any' station Will indicate on the appropriate such panel may also be provided with lamps or office panel a plurality of changed conditions' at other indicators controlled' `in -accordance with thefleld station-'for example, the entrance of 20 the conditions of the rseveral switches, signals, a train into atrack section and the consequent 20 etc.,` at the corresponding field station. restoration -to stop of a signal at the section It is-important that the .system by means of entrance.` l i which vthe field devices are controlled from the The code' transmitted consists of a series of imlunice and the office indicators are Igoverned from pulses certain offwhich are made of a distinctive .-1 the eld station ',(l) shall have a highv degree of character different from the other impulses. One V2li reliability, bothas to continuity of operation and featureof -mylinvention is that each impulse of freedom from' accidental or improper actuationg' distinctive character of a transmitted code ac- (2) shall require aminimum of apparatus,there tuatesv the vreceiver at the transmitting point, byV economizing infcost and .size of installation Whether ofi-leerer station, and is there registeredv 30 vand (3)v shall consume. a minimum amount of just as if the impulse had been received from an- 3() time in its operation thus utilizing most eco other transmitting point, and the transmitter is nomically the line facilities that'connectthe of'v locked to prevent the transmission of the next nce, With the field'stations and expediting the impulse' until this associated registration has controlwof traine fover the railroad on which taken'place. f the system is installed. The impulses arevdivided into groups and an- 35 ;In order.' to vaccomplish the above and other other feature of vmy invention is that the readvantageousobjects my invention incorporates ceiving apparatus at the transmitting station la number of novel features allv contributingvto responds to one transmitted impulse of this disthe achievement'of theA reliable, cheap and 'rapidtinctive character in a group to prevent the transg 15J-operating ysystem which isv its preferred emniitter 'from causing subsequent impulses in the 40 bodiment herein disclosed. same group to have the distinctive character.

f My invention is applied to asystem of the type Insystems of this character it is necessary to described in'which'transmitters, one at the ofdistinguish between codes transmitted from the nce and one at `veach' station, create codes made oflice andcodes transmitted from a field station.

4:; upv of elements.of-jdifferentiz'characters arranged In my invention I arbitrarily assign one impulse` v in patterns. An important feature of my invenv of each code vto'this function, and the transmittionv is that each codenot onlyselects the parters causethis impulse to have onecharacter in ticular office panel or eld station forl which it` alllcontrol code'soriginating at the oflice and 1-,0 is lintended butalsoigoverns each of a plurality have another character in all indication codes tu ci functionsy (switches, signals, etc., at the field originating `rat'the eld stations. In the event y50 stations or indicators at the` office) Whichl are that the oflice and a station vstart transmission associated with-.the selected point. To effectthis, at the same time, the character of this impulse each code.patternl is determined by the appacauses the office code to take precedence by lockratuslassoc'iated.With the transmitter, partsof ing'A out the cod'e from the eld station. The

es the pattern -ifnnction selecting) being deter-j .counting 'apparatus in the eld station receivers 55 the systemis free to transmit that code.

responds to this locking impulse as to the other impulses, but separate devices are actuated at the eld station one when the station is transmitting, which allows the transmitting operation to continue, and a.different one when the station is receiving, which allows that station to respond to the code and also prevents the transmission of a conflicting code from the receiving station.

Another feature of my invention is the provision for each office panel of a single starting button common to all the levers of a panel for initiating a single code which :transmits to the corresponding ield station information concerning the position of all the levers. With'this arrangement the levers may be manipulated to the positions required without affecting the code equipment, but if the operator .desires to-,control the eld devices in accordance with the `lever-positions, he can do so by a single operation of the starting buttonon the proper panel. This operation of the starting -buttcn initiates l.operation of the system and `automatically governs thedevices of Ythe eld `station into correspondence with the positions of .the levers-onthe oiice panel.

Another important feature of my invention is the provision of a starting relay and a selecting relay fioreach oiice panel together with novel circuits for lthe .control -of these relays. Each starting relay .is actuated by manipulation of thev same time, the several codes corresponding lthereto are transmitted sequentially, .the order -being determined lby code superiority.

,An important feature of my invention is the restoration of the starting relay -by fthe selecting.

relay. The ,circuits are so arranged that if the selecting relay is operated during oce receiving it will not restore the starting relay, but if the selecting relay isfoperatedduring o'ice transmission` the starting relay is automatically restored to its normal condition, This is a distinct advantage because it prevents the undesirabley repetition of a code from the office transmitter but allows storage of a control code, .after momentary manipulation of a starting button, `until Another important feature of my invention is the provision of means underthe control of the operator vforgverifying the indica-tions of the devices Aat any `station without changing the position of ,anysuch device. This is accomplished by providing, for each field transmitter, a starting circuit lwhicl'imay be lselectively closed bythe operator. In the particular embodiment illustrated, a .distinctive Vcharacter may be imparted to the code Voriginating at any oflice panel, and the resulting code will complete a special starting circuit-at the station responding to that code, whereupon a single indication code verifying the condition of all the devices at that station will be transmitted to the oiice. f

The .control and indicationfunctions of my invention .are all accomplished over a single line .circuit and it is important to check the condition of the line circuit at all tim`es.-A line relay is included in the line circuit at the oice and at each station. A feature of my invention is thev provision of two slow acting relays'for each line relay, one slow acting relay being energized when the line relay is 'energized and the other slow t acting relay being energized when the line relay isi deenergized. With this arrangement thelnormal intermittent operation of ythe line relay while a code is on the line results in both slow acting *relays being maintained .picked up. `If the line is steadily opener steadilyclosed this condition is manifested by the release of `one or the other of the slow acting relays. I

Another important feature of myinvention is the utilization of the slowv acting relays ymentioned above to control the counting relays used lin the :receiving and transmittingequipmcnt so as vto restore the apparatus.y to normal in the event of a line failurev priorto the completion ofacode. l v

@Still other important 4features Vof my invention reside in novellcircuits forcontrolling the relays of the 'transmitter and receiver that countthe impulses of ythe code. For this purpose lI pro- Vide a series ,of normally deenergized'relayscon'- nected in cascade `for operation through repeat-' ed cycles; Therelays of this .series are ener-4 gized and deenergized in sequence. During the rst cycle, in combination* with a switching contact closed onlvgyzduring that cycle, the counting relays provide a `plurality yof separatecontrol cir- At .the conclusionof the'rst cycle all cuits. 1311 Acounting .relays Vareenergized and ldeenergized sequentially throughasecond similar cycle.'v

During 'this second .cycle in vcombination .with a second switching contact closed'only vduringsuch second cycle, the counting relays :provide additional control circuits. 'lhis,-repeated operation is vaccomplished -With a minimur'n of apparatus because .each relay drops -out after fits, function has been performed,A and the repeated cycle operation permits a large number of counting operations with a small number of counting relays.

Another important feature .fof my invention is the utilization-of rectiers at.v numerous points throughout the circuits to accomplish -vit'al and valuable results.' Certain Vof these `rectifers' are connected across .the windings ofthe1 counting relays :to keep' the relays energized for a brief period afterthe circuits for the relays are opend. This'results vin a relay whichV isjquick to pick up but slow to release ,and contributesfmateri'ally'to the -uniform and lreliable operation `of the counting chains. Other rectifiers areconnecte'dacross the windings of the timing relays .which 'distinas f guish between code-impulses of different characters. -In y the preferred embodiment of. my in .p vention some impulses are short and others arej 6o y.

long, and certain of the timing relays andV their associated rectiiiers are adjusted so that each such relay will release on along impulse but not l on a short impulse. Rectiers arealso employed to retard the release of various .other relays so,

that they will remain picked up forgthe'duration ofacode.v

. As pointed out above, rmy invention is particularly applicableto systems ofl centralized'traic v control wherein'thel station devices are `railway Y switches, signals, etc., for the control of tralc along a stretch oi railway track.' In arrange-l` ments of this kind a field station-mayinclude `a track switch anda complement'of railwaysigvnais (usually four in number, one for governing train movements from each direction over each of office or from any station. All code signals are the two possible routes over the track switch) associated therewith. An important feature of my invention is the provision of means at a station vso equipped to position one polar stickrelay in response to certain elements of the code for switch control and to position another polar stick relay in response to other elements of the code for signal control. The first mentioned relay puts the signal for the existing route to stop, and .then actuates the switch to the required position, and finally signal controlling circuits are closed partly under the controlof the switch and its stick relay and partly under `the control of the signal relay for clearing the signal for the new route.

During the development of my complete system as herein disclosed, many important features have been `devised in addition to those discu'ssed at length above. Some of these additional features are applicable to systems of types quite different from that illustrated in the drawings, and all have advantageswhich are pointed out at length in the following specification.

In some specic respects the invention of this case is an improvement over the apparatus emp'loyed in the system shown in the copending application for Letters Patent of the United States Serial No. 255,375, filed February 18, 1928, by`

G. W. Baughman for Railway traffic controlling apparatus.

v I will describe one form of apparatus embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying` drawings, Figs. 1 and 2, when placed end to end with Fig. 1 on the left,

form a diagrammatic View illustrating a portion vpoint such as a dispatchers oflice, and also to indicateat the oiiice the condition of each of these devices. The traiiic governing devicesare here illustrated as switches and signals, each switch with its corresponding complement -of trackway signals being considered as one-station and a plurality of stations being controlled from the central office indicated in the drawings on Figs. l. and 2. The oiice and all of the stations are' connected together by means of a line circuit including two line wires DI and D2 which extend throughout the system. The line circuit vis at times supplied with current from a line battery N located at the oflice and under normal conditions the line circuit is closed through the back contact of a master relayand the winding of a line relay at each station and at the oiiice Each master relay is designated by the reference character T with a preiix correspondingl to the location, and is energized when sending and de-energzed when receiving.` Each line relay is designated by the reference character R with a prex corresponding to the-location, and is operated by the code signals both in Isending and in receiving.

The control of the various parts is accomplished by means of code signals transmitted over the line circuit including line wires DI and D2 from the made up of the samenumber of impulses each of which impulses is produced yby opening the line' circuit for a relatively short or long interval of time and again closing the line circuit for a short interval. The iirst impulse in each code is a locking` impulse,the function of which will be described hereinafter. Certain of the impulses following thelocking impulse in each code are used to select the station, thev number of such impulses required for `this purpose, depending` upon the number of stations to be controlled. In illustrating my invention, lI have assumed that twelve stations are to be controlled from the office and withthis arrangement seven station selecting impulses are necessary. The next impulses in each code are used to selecty the particular operations to be yperformed at thefselected station and with the apparatus here illustrated I require-seven impulses for this purpose. The last impulse accomplishes the operation of the devices at the selected station, and alsorestores the apparatus' to normal to prepare it `forthe reception or transmission of additional codes. The equipment also operates in a similar manner to rgisterthe condition of the station apparatus on an individual panel at the ofce. v

llVith the arrangement here illustrated,y each code consists of 16 impulses. One feature of my invention is the use of code signals all having the same number of impulses, but certain of which are prolonged to accomplish different purposes as will appear more in detail as the description proceeds.

For purposes of simplicity,.1 have illustrated only one station complete in the drawings, and have shown only that portion lof the ofiice equip" ment necessary for the control and indication of this one station, but it will ofcourse be understood that the other ll stations are similar in all respects to station 1 here. illustrated, but that thev additionalequipment requiredat the oflice will simply duplicate a portion of the vequipment here shown. i Located at station l is a stretch of railway track, (Fig.l 3), the rails of which are designated by the reference characters land la. Theserails are divided, by means of insulated joints 2, to form a track section 1 -bi, which contains ay switch 3 of the usual and Well known form, communicating with a lsiding 4. The section a--bI is provided with a track circuit comprising a track battery 5 and a track relay I'I'R. The rails of siding 4 are connected with the rails of section .a-b in the usual manner so that relay ITR is-normally energized but is de-energized when any part of a train occupies section a-b or the portion `of lsiding 4 to the left of point B. y

Eastbound traffic over switch 3 is controlled by signals ILA and ILB, which as here shown are mounted upon the same mast. Westbound traffic over switch is controlled by signals IRB and I RA.l Switch 3 is controlled by a motor IM which as here shown comprises an armature I5 and a field '1. The motor` IM is controlled in part by two switch relays i h andlk and also by a polarized relay IWS.

Assuming that all signals are in the stop position,l

when relay` IWS is moved tofits right-hand or reverse position, current ows from terminal Ix of a source of energy not shown in `the drawings, over front contact 8 of track relay ITR, reverse contact 9 of relay IWS, contact IIJ' controlled by the signals at station l., and winding of relay I h to terminal .Iy of the same source. Relay Ih therefore becomes energized and a circuit is closed from terminal Ix, lover front contact II of relay Ih, armature 6 of motor IM, back contact I2 of relay ik, front contact i3 of relay Ih, contact I-irla operated by switch Ei, and eld I of motor lM'to terminal Iy. Contact lli-lila is closed at all times except when the switch occupies its reverse position, andwhen the circuit justtraced is closed, the motor lIM is operated to move the switch to its reverse position. When the switch attains this position, contactiI-Illa opens to cle-energize the.V motor IM.

In similar manner, if relay IWS becomes energzed in its left-hand or normal position, current ows from terminal Ix, over front contact 8 of relay iTR, normal contact 8 of relay IWS, contact l llc controlled by the signals at station 1, and winding of relay Ik to 'terminal ly. Relay Ik then becomes energized and since relay Ih is then deenergized, a circuit is closed from terminal Ix, over front contact l2 of relay Ik, armature 5 of motor EM, back contact il of relay lh, iront Contact I5 yof relay Ik, contact I-llib operated by switch t, and field l of motor IM to terminal ly. Contact I l-l db is vclosed at all times except when switch 3 yoccupies its normal position, and when the circuit just traced is closed, motor IM is operated to move the switch toward its normal position in whichit is illustrated in the drawings. When the switch attains this position, contact MM! ib opens to cle-energize the motor.

Contacts ic and Illa controlled by signals at station 1 are operated, by means forming no part of my present invention and omitted from the drawings, in such manner that these contacts are closed only when signals lLB, SLA, lRB, and ERA all indicate stop. Contact ma is included in the pick-'up circuit for relay Ic and contact il) is inu eluded in 'the pick-up circuit for relay Eh, and it follows thatthe switch cannot be operated 'in either direction unless all o the associated signals are at stop. Furthermore, if a train is approaching the-switch within the limits of section 1f-b, relay lTR will vbe desenergized and under these conditions also it is impossible to .operate switch 3, because front contact 8 of track relay ITR. must be closed to energize either relay lh or Ik,

In practice, contacts i@ and 'ila may be so controlled as to prevent operation of relays lh and Ilc when a train occupies either the section to the let of a, or to the right of b, and is approaching section, a-b this so-called approach locking" is however omitted from the drawings because it forms no part of my invention and is a feature that is well known in therailjvvay signaling art.

Signal ILA is controlled by a relay iLAlI-I,

which relay is in turn controlled by relayfIVv'S and by two other polarized relays IHS and I FS, The circuit for relay ILAH may be traced from terminal im, over front contact 8 of relay iT'R, normal contact 9 of relay IWS, contact IIB-|60'. operated by switch 3, normal Contact Il of relay IHS, normal contact I8 of relay IFS,contact lil-ISU, operated by switch 3, and winding of relay I LAI-, to terminal Iy. Thiscircuit is closed only when relays IWS, IHS, and IFS` all occupy their normal positions and when the track relay lTR is energized and the switch occupies its normal position. When relay ILAH is energized, current is supplied to the operating mechanism of signal ILA over front con-tact 20 of this relay and the signal then indicates proceed. llt' relay IWS is energized in the reverse direction, switch 3 will also occuply its reverse position as explained hereinbeforaa-nd if relays IHS and IFS are Venergized .in the normal direction -zcurrent will then flow from terminal vIzc, over front rcontact ,8 of relay ITR, reverse contactQ of relay IWS, contact l-lb operated by switch 3, normal contactll'i of relayA IHS, normal contact I8 of relay iFS, contact lQ-ISIJ operated by switch 3, 'andwinding of relayl ELBH to terminal fig.. When relay iLB'H is energized, curr-ent is sup# plied to the operating mechanism of signal ILE,

over front contact r2i of relay lLBH and that signal then indicates proceed. i

If, however, relay iWS is energized in the normal direction so that switch 3 occupies its normal position and if relay IHS is energized Vin the normal direction and if relay IFS is energized in `the reverse direction, current flows from terminal im, over front contact 8 of relay I'I'Rj, normal contact 9 of relay lWS, contact Iii--Ia operated by switch It, normal contact I'I )of `relay-` IHS, reverse contact I8 of` relay IFS, contact 2I--2 Ia operated by switch 3 and winding of relay lRAI-I-to terminal iy. ,'When this relay is energized, cur-rent is supplied over its front contact 23 to the operating mechanism of signal `iRA which signal then indicates proceed. Finally, if relays IWS and IFS are both `energized in the reverse direction and lif relay IHS is energized in the normal direction, current ows from terminal Ix, over front contact S of relay I 'I"R, `reverse contact 9 of relay IWS, contact Iii-4th operated c by switch 3, normal contact lil oiirelay l HS, re.L

verse contact i8 of relay IFS, contact 2I-2Ib operated by switch 3, Vand winding of relay IRBH` to terminal ly, and relay IRBH therefore bev-135" cornes energized, to complete at front contact ,24 thereon, an operating circuit for signal IRB, which thereupon indicates proceed.

It should be noted that the energizing circuit for each of the signal control relays 'lLAl-I, ILBH,

rIRAH, and iRBH includes the normal contact I'Il of relay lli-IS, so that if this relay is Venergized in its :reverse direction `to open normal contact I'I,

all of the signal lcontrol relays'will be de-energized, and all of the signals located at station l will indicate stop.

In practice. the signals` may be semi-automatic, that is to say. they may be moved only v from stop to caution by the apparatusherein cated ona suitable panel at the dispatchers office as shown in the left hand portion ofxFig. 1.l

It is of course understood that each of the remaining stations, not shown in the drawings, is

provided with apparatus similar to that 'just de` l scribed at .station 1 and the .oiiice is provided with a separate panel with corresponding levers foreach of the remaining stations. In addition ther provided with indicationv apparatus for 4giving the operator visual information concerning the condition of the switchand signals andof the detector track section at the vcorrespomling sta-v tion.

1n addition to the polarized relays above described vI have employed inthis appartus a nurnber of others, and it is to be understood that each polarized relay is of .the permanent `maa-net stick I to the two co-ntrol levers, each such panel is furing. relay OJ.

.type so designed thatl it will holdits contact firmly closed by the action of its permanent magnet in the absence of electrical energy. Also, I have assumed that eachrelay is arranged so that when current ows through a Winding from terminal :I: to terminal y from left to right, the left-hand contact will close, and that when current flows from right to left, the relayy will re-` verse to close the right handcontact.

As was stated above, the code signals delivered to the line circuit are made up of impulses formed by briefly opening the circuit. Each such impulse causes leach line relay R to become deenergized and when the line circuit is Iagain closed, the line relaysy again become energized. Each line relay controls a chainv of counting relays here shown inv Figs. 2. and 4 as sixteen in number and each designated by the reference character B with a distinguishing prefix corresponding to the location and a suflx corresponding to its position lin the chain. Referring particularly to the apparatus shown on Fig. 2, line relay OR controls a chain` of counting relays OBI, AOBIaL, etc.

, As shown, each B relay is used first in coinbination with relay' CI- and is then used againv in -combination with relay C2. Associated'with the counting relays are two slow releasing relays OKaand OK. The operation of the system de' pends to some extentr uponthe times required for the voperations of certain relays and for purposes of explanation I' have assumed definite values for certain parts, but it should be understood `that these values are not essential, but are mentioned .only by Way of illustration. For example, I have assumed that therelease value of relays OKa and OK are each 0.3 second. A relay OJ is controlled by front; ycontact 2 5 of relay OR and has a release time of 0.2 second. Associated also with relay OR are three timing relays OZ, OX, and OY, each'of which is so adjusted that the sum of its pick-up' and release times is approximately 0.1 second. The master relay OT also has a release time of 0.1l second.

OV is a transmitter relay whichl is comparatively ever, some of the` impulsesmay be prolonged so thatthe line circuit is open for substantially 0.4 second. With these preliminary remarks in mind, I Will now describevthe operation of the office counting relays in detail in response to the reception of a codesignal from a station. The rst impulse of the code de-energizes relay OR, thereby closing back contact and de^energiz It will beremembered that yrelay OJ has a release time of A0.2'second and this relay willl therefore -hold itsl iront contacts closed for impulses of normal value but ywill 'open its front contacts for prolongedl impulses exceeding l 0.2 second in length. The first de-energization of relay OR completes a ycircuit for the first v `counting relay OBI, over back`contact 25 of relay OR and contact' 2'I--28 of .relayOKALv so that relay OBI becomes energized. Furthermore, current flowsfrom terminal O over back `Contact 25 of relay OR, back contact 26 of relay OKa, and winding of relay OCI to terminal Oy. Relay OCI therefore becomes energized and when this occurs, a circuit is completed from terminal Ox, over back contact 25 of yrelay OR, con- .tact 21j- 28 rof relay OKa, front contact 29 of. relay OBI, contact of relay OCI, and winding of relay OKa to terminal Oy. Relay OKa therefore `becomes energized, whereupon, a stick 'circuitis completed for this relay over back contact25 of 'relay OR and front contact 26 of relay OKCL, At the same time, contact 5 21--28 opens, but iront contact 3I of relay OKa `is noW closed so that relay OBI is stuck up over its own front Contact 29, iront contact 3l of relay OKCL and backcontact 25 of relay OR.

`Furthermore, relay O CI is now stuck up over front contact 32 of relay OKa, back contact 33 of Irelay OBSa and front contact 34 of relay OCI; The pick-up circuits of relays OBI and OCI are now open at theback contacts 26 and 28 'of relay OKa. When relay OKa becomes energized, current is supplied to relay OK, over front contact 35 of relay OJ and front contact 36 ofrelay OKa. It will therefore beplain that the 'first de-energizationof relay OR picks up relays OBI, OCI, OKa, and OK.

When relay OR next becomesl energized, the circuitfor relay OKa islopened, but since relay OR is never energized for more than v0.1 second during the reception of a code, relay OKa and relay OK both remain energized until the code has been completed. Relay OCI remains energized over vfront 'contact 32. of relay OKa but the stick circuit for relay OBI is opened at back contact 25 oi relay OR when the latter relay picks lup.l Before relay OBI releases, a pick-up cir-` cuit is'closed for relay OBIa over front contact 25 of relay OR, front contactl 37 of relay OKa, and front contact 38 of relay'OBI. Relay OBI a therefore picks upV and sticks up over its own front contactj3ll,` so that relay OBIa remains energized after relay OBI releases When the second impulse of the code is received, relay OR again becomes de-energized, whereupon a circuit is closed for relay OBZ over back contact 25 of relay OR, contact 2l-3I of relay OKC and iront. contact 40 of relay OBIa. Relay 4OB2 thereupon becomes energized and sticks up over its own front contact 4I. 'Ihis second de-energization of relay OR. does'not pick up relay OBI' because the' pick-up circuit for the latter relay is openl at c0ntact2128 lof relay OKa. Relay OBIa releasesat the conclusion of a brief interval; afterthe de-energization of relay OR. As relay OR becomes successively energized and cie-energized during `the remainder of the code, the counting relays B are energized successively. Each of these -relays is energized over a front contactof the preceding relay in the chain and sticks up `overits own front contact until the next operation of relay OR.

When the 8th impulse is received, relay OBB becomes energized and when relay OR next becomes energized, relay OBBU. picks up. When this happens, the stick circuit for relay OC I' is interrupted, but before relay OCI opens its front contacts a pickf-up circuit `is closed for relay OCIa, which pick-up circuit may be traced from` terminal Oar, over front contact 25 of relay OR,

yfront4 contact 31 of relay OKa., front contact 240 of relay OBB, frontI contact 42 of relay OCI, and winding of-relay OCIato terminal Oy. Relay rsi.

OCIatherefore. becomesl energized.` at. the same time as relay 0138er, and relay OCIa sticks up over a circuit including its own front Contact 43, front con-tact 2M of relay OBBa, front contactv 3l of relay OKa, andi front contact 25 of relay OR. Relay- OC I` becomes de-energized soon after relay OBSa, picks up, ancllvvhen relay OR next becomes (ie-energized., relaysV OBa and OC'Iafbecome cle-energized. Current noW flows from terr minal' O, through back contact 25 `ofrelay OR, contact 2`l-3Iv of relay OKa, front contact @6 of relay OBa, front contact M- of relay OCia, and Winding of relay OCE', to terminal Oy. Relay OCZ is therefore energized and isl subsequently stuck upover its own front contact 45 and back contact 33' of relay @BGG/ Furthermore, when relay OR became deeenergized, a circuit Was completed for relay OBI- from terminal Oar, through back contact 2t of relay OR, Contactv 2`I-3I of relay 0K0., fron-t contact l of relay OBBa, and Winding of relay OB I- to terminal Oy. This pickupcircuit opens, of course, as soon as relay OBB@ releases, but relay OBi is thereafter held in its energized condition over thestick circuit previously traced for this relay. As the succeeding impulses of theA code are received, relays OBIa, CB2, OBZa, etc., are energized successively. ItJ will be plain, therefore, that during the reception or transmission off a code of sixteen impulses, the counting relays B- are energized. successively through two complete cycles, relay OCI being energized during the first cycle of operation of the counting relays, andrelay OCZ being energized during the-second'cycle of operation of the counting relays. At the conclusion of the code, relay OR becomes energized and remains in this condition. Relay OKa. is therefore de-energized andA at the expiration of 0.3 second, this relay releases. Relays @B3n and OC2'release almost immediately, and relay OK releases at the end of 0.3` second following the release of relay OKa..

It Willi be notedv that since the release time cf relay OJ is 0.2 second,"this relay Willremain energized .during the intervals that relay OR is deenergized as long as these intervals do not exceed 0.2 second. WhenA a prolonged impulse is received, however, that is, When relay OR becomes de-energfized, for more than 0.2 second, relay OJ opens., and' remains open until relay OR is again energized. The function of relay OJ' will be described hereinafter.

It should also be pointed out that if relay OR remains energized; during the reception of a code for a longer time than the release time of .relay OKa, the latter relay Will become `cle-energized, thereby opening relay OK and also cle-energizing relay OCI or relay OCZ and Whichever one of the counting relays may then be energized. This operation restores the counting chain to its original condition and preventsvimproper operationl of a function due kto an incorrect code or accidental interruptions in the line circuit. The operation of theI counting relays at each station in response to yoperation of the associated line relay R is similar to the operationl just described and Will be understood from .the foregoing Without further explanation.

In explaining.I the operation of the apparatus I will assume that all parts occupy thepositions in Which they are illustrated inthedrawings and that the operator Wishes to restore signal. ILA= at station 1 to the stop positiorufrom the pro:- ceed position in which it is illustrated in the drawings. To accomplish thisl result the operator moves signal. control lever IJorr panell numenergico ber 1. to itsmidme position (see eig.. 1a, and than closes push button OPIS. TheA operation. of the push button OPI closes a pick-up circuit for re-y lay OI-Il. which Will be obvious from the draw-Q be released Without .de-energizing relayvOHLil.

When relay OI-II becomes energized, current flows from terminali Oar, through back contact Q91- of.

relayOT, front' contact Bil of relay ORI, and the lower winding cfa polarized starting relay OH, (Fig. 2) to terminal Oy. Relay OH theree forev becomesv energized. `in the reverse direction andlswings:itsarmature tothe rightto close con.- .fe

tact. 5i.. Currentthen flows fromfterminal Ox,

overv back Contact. 32. ofA relay 0K0., kback contact 52 of'` relay OK, reverse Contact 5i of relay OH andil Winding offjrelay OT to. terminal Oy.. Relayi Oitherefore becomes. energized and opens theline circuit including line Wires DI and D2. at backcontact of this relay. Relay OR therefore becomes rie-energized., picking uprelay OB If, OC l OKI, andOK' as describedhereinbefore. relay` OKa first becomes energized, the pick-up circuit previously traced for `relay OT. is interrupted, but relay OT-has a release time of 0,'1 second and. before this` relay opens, a. stick "circuitisclosed from terminal Ox, over front contact, 321 of relay OKa, front Contact 5s. of.` relay OIL.. front contact 5K5 of relay OT, reverse con-l tact'. 5t of. relay OH, andk Winding of. relay OT When When relay OR became de-energized and l picked. upfrelays OBI. and OCE, amok-up circuit was completedforrelay OE; which. may betraced from.y terminal 0st,: over back contact 25 of relay OR, (Fig. 2.). back. contact 25. of'relay OKa, front contact 5.6. (see: Fig. l.) of relay OCI, front. contact 57 of relay OBI., and Winding of. relay OE, to terminal O'yl. Relay OE therefore became energized, and is stuckup/by current which flows from terminal Ox; (Fig. 2) over front Contactv 32 of. relayfOKa, frontv contact 54 of relay OK, back contact-5a of relay 0112,. (Fig. 1) back Contact 5.9.1 of.' relay OLi, and` front. contactil of relayOE.

When: relay @.T became energized, the closing of front contact 6I. thereon'cornpleted a. pick-up circuit for relay OX, (Fig. 2) Which maybe traced from terminal Osc, over front contactGI. of relay OIT, back contact. 6.2'. of relay OY, and

winding of. relay OX toterminal Oy. Relay OX isf therefore. energized. and current is. supplied tol 55.

circuitv is completed for relay OX, from.terrni. nal Om, oyer'front contact Stof relay OFI', front contact S8 of. relay OZ,and.w.inding of relay OX tol terminal Oy;A The. opening of backcontact 6,2A

of relay OY interrupted the lpick-up circuit for relay'OX, but this relay is Anow held in its ener-v gized.l conditiony over the additional circuit just traced. 4Sincerel'ay OT is now renergized andv OV de-energized, the line circuit is held openuntilv i v relay OJ opensfwhich will' occur at the e'Xpiration..o'f-0.2i second after the.` operation ofL relayqgf .6I of relay OT, back contact63 of relay OX, front contact 69 of relay OY, and winding of relay OV to terminal Oy. Relay yOV therefore becomes energized and closes the line circuit through front contact 'I0 of relayvOV andfront contact 53 of relayvOT. Relay OR then again becomes energized'but it should be noted that theline circuit has been held open during `the first impulse for a time interval equal to the sum of lthe release times of relays OJ OZ, and OX. The y length ofthe first impulse is, then, approximate"u lly 0.4 second.4

. of this relay breaks the circuit for relay OW,

which immediately releases to again interrupt the line circuit. rThis initiates ythe second impulse, de-energizing relay OR and picking up relay CB2.

When vrelay OYbecomes l(ie-energized, the pick' up circuit forrelayl OX is again closed and this relaybecomes energized. Relay OY is then picked upvover front contactv63 of relayOX, and front contact 6I of yrelay OT. `The opening of back contact 62er relay OY .interrupts thepickup circuit for relay OX, but lrelay OX is now held up over a holding circuit which Amay be traced from .terminal Oar, (Fig. 2), over front contact 6I -of relay OT, front contact M. oi relay OCI, front contact 'II of relay CB2, front contactIZ of relay OHI on panel number 1, front contact 13 of relay OE, and'winding of relay OXto terminal Oy. Since relay OR is now `de-energized, relay OJ is also deenergized, and "releases after 0.2 second.

yWhen-backcontact 35 of relay OJ closes, current flows from terminal Ox, over back contact35 of relay OJ, front contact "I4 of relay OCI, (Fig. 1) front contact 'I5 vof relay OE, front contact 16 of relay OBZ and lwinding ofa'group selector relay OGI, to terminal Oy. Relay OGI therefore becomes energized, andcurrent thenows over the l circuit just traced, as far as front contact 'I6 of relayOB2, and thence over front contact 'I8 of relay OGI and-winding of relay OLI Lto terminal Oy. ,Relay'OLL therefore, also becomes energized, interrupting the stick circuit previously traced for relayOE. Relay OE therefore releases and relays OG! `and OLI are held.' energized over 4stickcircuits vincludingI their own front contacts, back contact 58.0f relay OL2, front contact 54 lofrelay OK and front contact 32 of relay OKa.

The opening` of front contact 'I3 (Fig. `2) of -relay OE breaks the holding circuitl for relay OX and this relay'therefore releases to' close back contact 63 and complete the circuit for relay OV.

-, It will therefere be seen that the line circuit has been opened during the second impulse for a When relay OV becomes energized, relay OR` picks up and `energizes relay OB2a.. Further more, the opening of relay OX de-energizes relay OY and, after 0.1 second, this relay opens to again complete the circuit for relay OX;` .v .When

relay OX picks up, relay OY becomes energized, thereby breaking theicircuit for `relay OX. Un-

der these conditions, there is no holding` circuit for relay OX, `because relay OE is now de-energized so that its front contact 'I3 is open, and relay OX therefore becomes cle-energized. W'hen this relay closes its back contact 63, relay OV becomes energized to close the line 'circuit and pick-up relay OB3a. It will be lseen therefore that the third impulse is not prolonged but is equal to the pick-up 'time of relay OV, plus the pick-up of relay OX, plus the release timeof relay OY.` f

continues, and relay OV operates periodicallyto open and close the line circuit, and causes the repeated operation of relay OR in the manner described until the 5th impulse has been tran..- mitted to the line circuit. At the beginning of the 5th impulse, relay OBE isl picked up and a holding circuit is then closed. for relay OX which may be traced fromterrninal Ox, over front contact 6i of. relay OT, iront contact 64 of relay OCI, front contact 'I9 of relay OB5, front contact 80 of relay OHI on panel numberl Lxfront contact 8I of relay OGI, andwinding of relay OX to terminal Oy. Relay OX is therefore held energized to prevent energization of relayv OV The pumping operation of relays OXvand OY- until relay OG! becomes de-energized. This i takes place inthe followingplanner.:l The opening of the line circuit for the 5th impulse'opens relay OR and de-energizes relay OJ, and 4at the conclusion of, its holding time relay OJ dropsv to close its back Contact 35. The closing of this contact completes a circuit from terminal 0.1.',

over back contact of relayr OJ, iront Contact I4 (Fig. 1) of relay OCI, front contact 82A of relay OB5, front contact 83 of relay OGi, and'winding lof the' panel selector relay-OSI to terminal Oy.

Relay OSI therefore picks up, and current flows over the circuit just traced `as far as front contact 83 of relay OGI, and thence over front con tact 84 of relay OSI, and winding of relay OLZ to terminal Oy. Relay CL2 therefore becomes energized to open its back contact Ei? and break the stick circuits previously described for relays OGI and OLI. Relay OGI therefore becomes de-energized, breaking the pick-up circuits just traced for relaysV OSI and OL2,but relay O-L2 is now stuck up over its own front contact/58, front contact 54 of relay OK, and fronty contact 32 of relay OKa.. Furthermore, relay OSE is now stuck up over its own front contact 84, front contact 58 of. relay OL2, front contact aid of relayv OK, and front contact 32 or" relay `OKci,l and relay OSI breaks the holding `circuit yfor relay OHI so that this relay now becomes fie-energized and' itscontact 50 opens to deenergize polarized starting relay OH. Contact 5I of the latter relay remains closed until relay .'OH is reversed at the end of the code signal as will be described hereinafter. The opening of irontcontact 8l of relay OGi. breaks the yholding circuit for relay OX,

and, after the release interval oi this relay has elapsed, the back contact 63 `or" relay OX closes, picking upl relay OV t'o terminate the 5th impulse by rre-establishing the line circuit. .It will be seen, therefore, that the 5th impulse is prolonged to have the same length as the second impulse. The pumpingl operation of relays OX and OY then continues.

At. the conclusion of the v8th impulse, relays OBa and. OCla become energized as described hereinbefore. The 9th impulse thereforepenergizesrelays OBI and OCthe latter relay remaining; energized during subsequent impulses delivered to the line. Relay OBil releases; after relay OR becomes energized at the end of the 9th. impulse. As the transmission oi. the code continues, due to operation of relays OX, OY and OB, the counting` relays Oliv are successively energized until the llth impulse is` .delivered to theV line circuit. The transmission of this impulse to the line circuit' results in the energization of relay DB3 and since relays OCZ and OSI are now energized, current flows from terminal Oa', over front Contact iii of master relay O'l,` front contact 35 yof relay OCE, front contact M3 of relay OS l lever ld in itsleft-hand position, upper winding of, relay OWDt, front contact i239 of relay OBS., front contact eli of. relay OJ, iront contact Gl of relay OX, and winding of relay OZ to terminal Oy.. Relay OZ therefore picks up` and completes the additional circuit. for relay OX, over front contact GS of relay OZ, ,and iront contact Gl of relay OT. Relay OX is therefore held energized to prolong the 11th impulse until relay OZ becomes cie-energized. Since relay OR is now de-energized, relay O5 isv also fle-energized, and after 0.2. second iront contact. 65 of relay OJ opens to de-energize relay OZ. After 0.1v second, relay OZ opens to cie-energize relay OX, and. 0.1 second later back contact. 63 of relay OX closes to complete the pick-up circuit for relay OV, thereby rra-establishing the line circuit and terminating the lith impulse. It Will be seen, however, that the llth impulse has been prolonged. to 0.4 second to transmit as the 11th element of the code a signal. indicating that lever Id is in its left-hand position. The `:repeated operation of relays OX and OY then continues, and short impulses aretransmitteduntil the 14th impulse is reached, when the energization of relay OB permits current to flow from terminal Ox, front contact 5l of relay OT, iront contact of relay OCZ, front contact 86. of relay OSI, lever l f in its middle postioniront contact Sl of relay OBl, front contact Gli of relay @liront contact 6l of relay OX and Winding of relay OZ to terminal Oy. Relay OZ therefore. picks up to prolong the 14th impulse in a manner similar to that just described for the lith impulse.

Subsequent. impulses in the code are short, until the nal or 16th impulse is transmitted to the line, this last impulse being prolongedfto form the delivery impulse oi the code asiellows: The commencement of the 16th .impulse de-energizes relay OR and picks up relay OBS. A. ycircuit is therefore completed from terminal Om, front contact 6l of relay OT, iront contact of relay O02, (Fig. 2) upper Winding of starting relay OH, front contact 3 oi relay OBS, front Contact 66 of relay OJ, front contact (il of. relay OX, and Winding of relay OZ to terminal Oy. When-this circuit is closed, relay OZ is energized to complete the holding circuit for relay OX and prolong vthe 16th impulse.A Furthermore, current delivered to this circuit restores the starting relay OH to its normal position, thereby opening reverse contact El of this relay. The opening. of reverse contact il of `relay OH interrupts the stick circuit previously traced for relay OT, but this relay is. nowv held in its energized condition by Virtue of a brancl'i including front contact 89 of relay OZ, now closed around Contact 5l of relay OH. Since relay OZ is energized, therefora, relay OT. remains energized... When.- relay OJ opens its front Contact 55?: at the conclusionof. its holdingv intervaly it` de-energizes relay;v OZ,

Frontcontact of relay OZ thereforeybreaks the stick circuit for relay OT, whereupon relayOf-` becomes defenergized to close the normal line circuit over its back contactl 31 -t will` be seen,

however, that the line circuit has been held `open during; theV 36th impulse-tera time intein/al equal' te the sumof the homing times of, reiay'soi, oz,- f

and OT so that the final impulse is a long impulse of the vsame length as the other. long' tmlpulses. Relay OR nowremains energized, so that after 0.3 second relay Olio becomes Vle-energizec l.

all relays except OR, OJ, and'O-K are' now de-y energized to kreturn .the apparatus to its normal position so that after 0.3 second theapparatus is iny condition to receive code from a'. station,

The de-energization of relay Olio deeenergizes'.` A'

relay OK so-that Olli." second later it closes itsiba'ck Contact to prepare the pick-up circuit for relay OT.. Thisy circuit is nowv openat Contact .5l of relay OI-L: and the apparatus is in a condition to send a control code as vsoon ascontact 5l is again closed". This time interval' betweenY the release or relays Kc. andjl at eachstation. insures that, all stations are incondition to receive before any station startsy to send.

InV the foregoing explanation `I.havedescribed.; the operation of the apparatus at theolce `during the transmission of a control code'to theline Wires and it will be seen'. that this code consists of i6 impulses, the lst, 2nd, 5th, 11th, letlnand 16th of Which areapproximatelyflle',secondwin f "i length While the remaining impulses are approximately 0.1 second in length.v

I Will now` describe. the operation of the rap-` paratusat station No. l in response to the con-l,` trol code thus supplied to the line-J circuit.y It should be borne in mind that theI operation 'of the apparatus at the remaining stati'onsis sim-- il'ar all respects to the operation of they apef paratus at station l exceptjthat theseveral sta.-

tions. are selectively rresponsii/"etou the location in the code signal of the 2nd and .3rd long. im?" pulses, and. onlystation `1 Willbe responsive toV the particular code signal just described. Referring now to the equipment illustreutedonV Figs 3 and. 4 and located at station No.l l, the. first impulse ofthe code signal transmitted'from the ofiice deenergizes relay lR,jto"C10sej"back contact Sil' and pick-up relays 5B1, ICL; IKM,I and IK, each of these relays remaining its` energized condition by virtue' of stick circuitsl similar to those already described' invv connection With Figs. l` and 2, Furthe1mcre,"this de-"ene'rf` back contact Eil and completing a circuit from' terminal Ix, over back contact Sl'of'relaylJ', front contact 9i. ofrelay l'Cl', front contact 9'3' of relay EBI', and winding of a lock out 'relay 'iE to, terminal ly. Relay Illi's sub sefqu'ently.heldinits` energized condition by virtue 'of aj stick .circuit which includes the front contact'. Sit of relay v v front contact er' relay iKandfront Contact' 96k of relay lKa. Duringy the'interval betweenv zo i the 1st and 2nd-impulses, relay iR is` energized: so that relay 'E J again picks `upland relay lBla picks up, and relay IB! releases. During kthe second impulse, relay IR is againdeenergized pickingjup relay LBL and releasing relay IBM.'`

It will be remembered that the second impulse is l also long, so that at the conclusion of the holding interval of relay IJ, that relay closes its back contacts, and current then flows from terminal Ix, over front contact 96 of relay IKa, back contact 91 of relay IB8a, front contact 90 of relay ICI, front contact 99 of relay ICI, front contact of relay IB2, jumper |0I,lback contact |02 of relay IJ, front contact |03 of relay IE, and Winding of the group selector relay IG. to terminal Iy. When relay IR next becomes energized, relay IJ picks up and relay |B2a also picks up, but relay IB2 becomes de-energized. As a result, the pick-up circuit just traced for relay IG is open, but this relay is now heldenergized over a stick circuit including its own front contact |04, front contact 95 of relay IK, and front contact 96 of relay IKoL.y The third and fourth impulses are short and relay IJ therefore remains energized While these impulses are being received, and when the 5th impulse is received, relay IB5 will be energized. Since the 5th impulse is long, relay IJ opens at the conclusion of 0.2 second and acircuit is then completed for the station selector relay IS which may be traced from terminal Ix, over front contact 96 of relay IKa, back contact91 of relay IB8a, front contact 98 of relay ICI, front contact 99 of relay ICI, front contact |05 of relay IB5, Ajumper |06, back contact |01 of relay IJ, front contact |08 of relay IG `and winding of relay IS to terminal Iy. At the conclusion of the 5th impulse, relay IR picks up to energize relay IJ and continue the successive operation of the counting relays and the pick-up circuit just traced for relay IS is then open., butthis relay remains energized, its stick circuit beingl closed over its own front contact |09, front contact 95 of relay IKa and front contact 96 of relay IK.

Subsequent impulses in the code are short until A y the 11th impulse.

It should be noted that the beginning of the 9th impulse will find 'relay IBa-picked up` and will also iind relay ICIa picked up. The 9th impulse, therefore energizes relays IBI and IC2 and de-energizes relays IB9a and ICIa. When the 11th impulse is received, relay IB3A will become energized and since this impulse is long, relay IJ will become de-energized at the end of 0.2 second to close a circuit from terminal Ix, over backcontact 9| of relay IJ, front contact IIO of relay IC2, front contact III of relay IS, front contact |40 of relay IB3, and winding of register relay IF3 to terminal Iy. Relay IFS is subsequently held up by a stick circuit including its `own yfront contact I4I, front contact 95 of relay IK, and front contact 96 of relay IKa. The 12th and 13th impulses are short so that IJ does not close its back contact and therefore relays IF4 and IF5 are not operated. The 14th impulse is long however, and results in picking up register relay IFS over contactk |I2 of relay IB6 and thisrelay then sticks up over its own front contact II3 in a manner vsimilar to' that just described for relay IF3. During the 15th impulse, whichv is short, relay IJ is not de-energizedlong enough to close its back Contact. When the 16th vimpulse is -received, however, relay IBB picks up, closing its delivery contact II4, and'since this 16th impulse is long, relay IJ closes its back Contact 9|. An operating, or totalizing impulse is then delivered to relay IWS, (Fig. 3) over acircuit which passes from terminal Ix, over back contact 9| of relay IJ, (Fig. 2)l front contact |I0 of relay IC2, front contact ,I I-I of relay IS, ffrontlcontact II4 of relay IB8, front contact |42 of relay vIF3 and the upper winding of relay I WS to terminal Iy. This impulse tends t'o move contact 9 of IWS to the left, but since this contact is alreadyin that position, no change results. A branch of the sameA circuit also delivers an operating impulse to relay IHS, from front contact |I4 of relay I B8, front contact I I5-'of relayA IFS and the upper winding of relay IHS to terminal Iy. Relay IHS is therefore energized in the reverse direction, to open the normal contact I1. The interruption of this contact breaks the circuit for relay ILAH which thereupon becomes de-energizedv to open, at front contact 20, the operating circuit for signal ILA, to put this signal to its stop position. It should be pointed out that had any of the other signals been indicating proceed, the reversal of relay IHS would have put suchffsignal to the stop position. If, due to line trouble or other causes, the total number of impulsesy received at station 1 is greater or less than 16, the delivery impulse will be received by some counting relay other than IB8, and polarized relays mains in its reverse position.

I will next assume that the operatoninstead of moving signal control .lever If to its middle position to set the signals at station No. 1 at stop, r

wishes to clear the westbound signal at this station. I-Ie accomplishes this result by movinglever ,Ify to its right-hand position, and closing the starting push button OPI, The apparatus at the oiilce is then set into operation to send a code in the same manner as already described withthe exception that the 15th impulse is now prolonged instead of the 14th impulse. This change is accomplished in the following mannerzmAs Was l pointed out hereinbefore, when lever If is'in the middle position, relay OZ becomes energized during the 14th impulse to prolong this impulse, the circuit for relay OZ including front contact 81 of relay OBB and lever If in its middle position. `Since lever If nowy occupies its right-hand position, this circuit is open and the 14th impulse is short. During the 15th impulse,however, relay OB'I -is energized. and a circuit is completed for relay OZ,y which may be traced from terminal Orc, over iront contact 6I of relay OT, front contact 85 of `relay OCZ, front contact 86 of relay OSI, lever If in its` right-hand position, lower winding of relay 'OFDI, front contact |.I6 vof relay DB1, front contact .66 of relay OJ, front contact 61. of r'elay OX, and winding of relay` OZ to ter- ,'minal Oy. Relay-OZ is thereforel energized, and

it will be plain that the 15th impulse has been prolonged. It will be seen, therefore, that the code now transmitted to the line circuit consists of v16 impulses, the 1st, v2nd, 5th, 11th, 15th, and

'16th, of which are long impulses while the remaining impulses are short impulses.

It should be noted that current supplied to relay OZv during the 15th impulse energizes relay` OFDI, and swings contact |22 of thisfrelay to its reverse position. This breaks the circuit ofthe signal indication lamp |21, which when lightedv indicates that the veastbound signal at station I is-cIear, and thus informs the operator that the code to reverse they traino direction has been sent. Contact |22 in reverse position connects lamp |28 to terminal Oy, preparing a circuit so that the signal indication lamp i123 may be lighted as soon as relay OFKI is reversed by a return indication showing that the signal at station l has cleared for Westbound tramo.

Referring now to the `apparatus at station No. 1, the code signal just described will actuate the apparatus at this station in the manner already explained, except that register relays IFS and IFI will be energized instead of IFS and IF, This takes place as follows: During the 15th impulse, relay IBI is energized and sincethis impulse is long, relay IJ releas and a circuit is completed from terminal Ix, over back contact 9| of relay IJ, front contact IIII of relay SC2, front contact II I of relay IS, front contact I I 'I of relay IB'I, and winding of relay IFT to terminal Iy. Relay IF'I therefore picks up and sticks up over a circuit including its own front contact'I IS, front contact d5 of relay IK and front contact 96 of relay IKct. When the 16th impulse is received, relay IBII is energized and since this impulse is long, relay IJ releases `and current flows from terminal Ix, over back contact @Iv of relay IJ, front contact III) of relay IC2, front contact' III of relay IS, front contact IIII, of rela-y'k |338, front contact |62 of relay IFS and the upper Winding of relay IWS to terminal Iy, tending to movecontact Ilto the left; also from front contact Iizl of relay IBS over frontcontact IIS ofrelay IF'I, lower winding of relay IHS to move its contact Il to the left, if not already in that position; and also from front Contact IM of relay IBS over front container I2@ of relay IFI and the lower winding of relay IFS to move its contact I8 to the right. This operation of relays I HS and IFS deenergizes relay ILAH, if that relay happens to 'be energized, and also completes the circuit for relay IRAH. Relay IRAH therefore becomes energized and completes at front contact 23 thereon the operating circuit for signal` IRA which signal then indicates proceed.

' I will next assume that-the signal control lever.

I has been moved to either its middle or righthand vpositions to send out a carresponding code as already described and that the operator then restores the lever' I f to its normal position in which it is shown in the drawings, and then operates the push button OPI, to transmit tov theline circuit a code whichwill clear the eastbound signal at station No. l. When the pushbutton OPI is operated the apparatus at the office is actuated 'to transmit to the line circuit acode similar to I those previously described, except that in this caserthe long impulses will be the lst, 2nd,'5th, 11th,- 13th, and 16th. Since lever I f now occupies its-left-hand position, a circuit will be closed for relay OZ during the 13th impulse when relay DB5 isy energized, which circuit passes from terminal Ox, over front contact @I of relay OT, front contact 35 of relay OCZ, front contact 86 of relay OSI, ylever` If in its left-hand position, upper.

*winding of relay OFDI front contact IRI of relay 0135, front contact S6 of relay OJ, front contact 67 of relay OX, and Winding of relay OZ to terminal Oy. Relay OZ therefore becomes energized to hold relay OX energized andprolong the 13th impulse." Since the circuit just traced includes the operating winding of relay OFDI, this' relay lis energized in lits normal dir'ection'to close normal .contact- |22, and prepare the circuit `for lighting lampv I 2l upon the receipt of `a normal indication, as will be explained in detail hereinafter. Had the'signal control lever I f occupied its right-hand position previous to its last change, with lamp ,t28 energized, thisoperation ofrelay OFDI would The Ycodetransmitted to the line-circuit under the conditions just described, selects the equip-l ment at station No. l inthe manner already describedl to pick upy relays IE, IF, and IG.

impulse is long, as v During the 11th `impulse register relay-IF3 is picked up over contacty |46 of relay IBS asalready described. During the 13th impulse, relay IE5 is,v of course, energized, and at this time, relay ICE is also energized. Since the 13th 'impulse is long, rrelay IJ releases and currentthen flows from terminal Im, over backcontaot 9i of relay IJ, front Contact II-Il` of relay ICE, front contact III of relay I-S, front'contact I'Zof relay f IBIi, and Winding of relay IF5 to terminally.

Relay I F5 therefore becomes energized, and sticks up over a circuit including its own front conl tact I2l, front contact 95 of relay IK, and 'front contact B of relay I Ka. Since the 14th and 15th impulses are short, relays IFE and IFIl remain de-energized. When the 16th f impulse is received, relay IBB is energized and since this impulse is long,V the delivery" circuit is closed and current flows from terminal Im, over back contact 9| of relay IJ, frontcontact I I Il of relay I C2, front Contact III of relay IS, front contact II4 of relay B8, front contact l2 of relay F3, and the vupper winding of relay IWS to terminal Iy. Relay I'VVS thus receives an impulse tendingA to move contact to the left; A branch is closed for the circuit just traced from front contact I4 of relayy IB8, over contact |25 of relay IE5 and the ylower winding of relay IHS to terminal Iy,

to movelcontaot Il to the left, if Ynot already in that position and a second branchl circuit is closedl from front contact IM of 'relay IBS ovei contact I26'of relay `Ilupper winding of relay IFS to terminal I y to cause contact I8 to move' to theleft. 'Ihis operation of relays IHS and IFSl closes,atlc0ntacts I 'I and I8, the circuit-for relay 'ILAH and energizes this relayto clear signal ILA.

I will next assume that Vwith the apparatus inv '45 ings, the operator moves switch control lever IcZ`fV on panel No. 1 at the office to its right-handposin the condition in which it is illustrated in the drawtion to reverse switch 5i at station No. l.l He then closes push button OPI, whereupon the ap'- Daratusis actuated to transmit to theline ycircuit a code similar-to those -previously discussed butk f Y having the 12th impulse prolonged, the long impulses'in'thiscase being the 1st, 2nd, 5th, 12th,` 13th, and 16th.. This is accomplished in the following manner: When the 12th impulse cornmences, relay OBLI` is energized, Vand a circuit is front contact @I3 of relay OJ, front contact 6l of relay OX, and Winding ofy relay OZ to terminal Oy; prolong 'the '12th impulse. the circuit-*just traced for relay OZfalso ener- I 3| This lamp is therefore extinguished and informs the operator 'that a code hasbeen sent Relay vOZtherefore becomes energized to Current supplied to 'gizesrela-y-OWDI in its reverse direction, there l by openingVY at normal contact |39 thereon, the

lcircuit for the normal switch indication lamp "70 to reverse -Izlie's'witc'zl'iyv Reverse contact I'is closed to connect'the reverseswitch indication f lamp |32 toeterminal Oy, preparing a circuit so L.75.

` foo that lamp |32 may be' lighted when a reverse switch indication is received. `When the code just described isreceived at station No. l, relays IE, IG, and IS are energized as before, and when the 12th impulse is received, r-elay IB4 will be energized. Since the 12th impulse is long, relay IJ becomes de-energized and picks up relay IF4 over a circuit which may be traced from terminal Ix, over back contact 9| of relay IJ, front contact ||0 of relay IC2, front contact III of relay IS, front contact |63 of relay IB4 and winding of relay IF4 to terminal Iy. Register relay IF4 therefore becomes energized and sticks up over its lown front contact |31, front contact 95 of relay IK and front contact 96 of relay IKa. When the 13th impulse is received, register relay IF5\picks up as already described; and when the 16th. impulse is received,`the operating circuit is closed from terminal Im, over back contact 9| of relay IJ, front contact |||l of relay IC2, front Contact III of relay IS, front contact IIli` of relay IBS, front contact |38 of relay IF4, and' the lower winding of relay IWS to terminal Iy. Relay IWS therefore becomes energized in the reverse direction to swing contact 9 to the right. Furthermore, a branch is closed for the operating circuit over contact II5 of relay IF5 to energize relay IHS in the reverse direction, tending to close contact Il. Another branch for the operating circuit is also'closed over contact |26 of relay |F5 energizing relay IFS in the reverse direction and tending to swing 'contact I8 to the left; but it has been assumed that contacts I'I and I8 are already tothe left, so no movement of these contacts-takes place. It should be observed that the reversal of relay IWS breaks the circuit previously existing for relay ILAI-I. The` opening'of front contact 29 of relay ILAH restores signal ILA to the stop position, and when the signals at station No. l all indicate stop, contacts I0 and Ia. controlled bythese signals are both closed. Current then ows over reverse contact 9 of relay IWSto energize relay Ih, and motor IM is operated to move switch 3 to its reverse position. When the switch attains its full reverse position, the opening of front contact |4--I4a de-energizes motor IM. Furthermore, this operation of the switch 3 opens contact I -I 6a and closes contact lli-lh. A circuit is then completed for relay ILBH and this relay becomes energized to close the operating circuit for signal ILB. It should be observed that the transmission of a code for-reversing the switch and clearing the signal for the traiiic direction previously existing first puts all signals to stop, thenreverses the switch, and finally clears the signal which corresponds to the new switch position and to the traffic direction.

I will next assume that the operator wishes to restore switch 3 at station No. ll to its normal position, with traffic direction unchanged. I-Ie accomplishes this result by restoring lever I d yon panel No. 1y to its normalfposition, and operat- '.ing push button OPI. The code now transmitted from the ofiice has the 1st, 2nd, 5th, 11th, 13th, and 16th impulses prolonged, which code has yalready been described. Relay OWDI will be restored to normaL-during the transmission of thiscode, thereby extinguishing reverse switch indication lamp |32 had this lamp been previously lighted, and preparing the circuit of lamp I3I for the receipt of a normal switch indication.

When the code just described is received at station No. l, the 11th impulse will pickju'p register relay IF3 so that the nal operating impulse willl will be prolonged.

restore relay IWS to normal to close reverse contact 9. This operation of relay IWS de-energizes relay ILBH and puts signal ILB at station No. 1 at stop. Contacts I9 and Illa then close and a circuit is completed over normal contact 9.0i relay IWS for relay Ik. This relay therefore becomes energized and motor IM is operated to move the switch 3 to its normal position. When the switch attains its normal position contact I4;|4b opens to de-energize motor, IM, and contact I6-I6a closes to complete the circuit for relay ILAI-I. Signal ILA is thereforecleared and contacts IIl and I4 then open to prevent furthen operation of motor IM until all signals at station Number l have been restored to the stop position'.

In all of the preceding discussion, I have'considered only the transmission of control codes from the oce to station No. 1 and it will be seenl that each of these codes have the iirst impulse long and also the 2nd and 5th impulses long to pick-up the gro-upand station selector relays IG and IS at station No. l. It will be plain from an examination of Fig. 4 that relay IG is energized by a long second impulse in the code because jumper IUI connects back contact |02` of relay IJ with front contact of relay IBZ. Had jumper IUI been adjusted to connect contact |92 of relay IJ with fro-nt contact |44 of relay IB3, it would have been necessary to prolong the 3rd impulse in order to pick up relay IG. Similarly had it been adjusted to connect contact |92 of relay IJ with contact |45 of relay IB4, relay IG could be energized'only if the `Lith impulse of the code were long. Furthermore, by proper adjustment of jumperv |96, the apparatus could be arranged to pick up relay IS on codes having the `6th,` 7th, or 8th impulses long instead of the 5th as shown in n the drawings, by connecting |96 to the corresponding contact of IBS, IBI, or IB8 instead of kto contact Iii of lB5. It is apparent from the foregoing that the apparatus at the station can `be adjusted torespond to any one oftwelve different combinations of long impulses in the code and that each station will be selected only by the code having the proper impulses prolonged. Since none of the functions ata station can be actuated until the station selector relay at that station, corresponding to relay IS at station No. 1 has been energized, it follows that the station will be unaffected by any code except the one which is intended for that station, and of course', in practice, the jumpers IIiI and |96 at each of the twelve stations areadjusted so that each station will respond to a different code.

If a code is to be sent from the oflice for controlling apparatus at a station other than station No. 1, it will be accomplished byoperating appai ratus associated with the panel corresponding to such station in the same manner as already described in connection with panel No. ,1, the oce equipment including a set of twelve panels when there are twelve stations to be controlled. It will be seen that relay OI-II determines "when energized thatthe 2nd and 5th impulses ofgthe code starting relay H for a dierent panel is energized, rother impulses are prolonged to select the correspondingstations. The selection at the oflice between impulses is accomplished by the group of contacts illustrated at the left-hand edge of Fig. 2, where I have shown contacts for .twelve individual starting relays OHI to OI-IIZ inclusive, one

of which relays is associated with each of the twelve panels of the oice equipment. yEach "of these relays controls the selection -of -its yown If, however, the individuall ci i' panel and-station in a manner similar to `that described yfor the selection of panel No. 1 and static-n No. l by the operation of relay OHI.

The apparatus is also arranged to transmit from each station indication codes similar to the codes used for the control of apparatus at the station, for operating indication means at the oice in response to any change in the condition oi the apparatus located at the station. In explaining this feature of my invention, l will iirst assume that with the parts occupying the positionsin Which they are illustrated in the drawings, a train 4enters section a-b at station No. l and causes relay I TR, (Fig. 3) to become deenergized. When back contact M5 or this relay closes, current hows from terminal la', through back contact MB of relay I TR, normal contact It? of relay I TD, back Contact I of relay IT, (Fig. 4) and the lower Winding' of starting relay IH. to terminal Iy. Relay IH therefore becomes energized in the reverse direction to close Contact let. A pick-up circuit is then closed for master relay IT, which may be traced from terminal Ix, over back contact gli of relay IKa., back Contact Ill@ of rela-y IK.,` re- Verse contact I 58 of relay IH, and winding of relay IT to terminal Iy. When this circuit is closed, relayf iT becomes energized and this relay remains energized until a complete code has .been sent. The energization of relay iT opens its back contact |52, thereby interrupting .the portion of the line circuit extending to all stations beyond station 1, so that all line relays R at these stations are de-energized. Furthermore, the portion .of the line circuit extending from the transmitting station 'to the oice is open at contact ISS of transmitter relay iV,v and this opening of the line circuit de-energizes relay IR at 'the station and relay OR at the ofhce, and also the R relays of any stations located between the sending station and the cnice. The de-energization of relay IR at station No. l picks up relays IBI, ICI, lKa, and IK as will be readily understood Without further explanation. Relays Ilia and' IK remain energized until the code has been completed. It will be plain'that the energization of the two relays last mentioned interrupts the pick-up circuit just traced for relay IT, but this relay is noW held energized over a stick circuit including front contact Q6 of relay IKa, front contact 95 of relay IK., back contact 94 of relay IE, front contact I5I of relay IT and reverse'contact I5@ of relay IH.

When relay IT picked up, relay IX was energized over back contact ISE of relay IY and iront contact IIS-'i of relay iT. When relay iX becomes energized, relayy IY is `picked up, over front contact 15?' of relay IX and front contact IMsofl relay IT. The energization of relay IY breaks the circuit for relay IX and after a timerinterval, relay IX opens. When this happens, relay IV is energized over front Contact IE5 oi relay IY, back contact I5? of relay IX and front contact l94 of relay IT. Relay IV therefore becomes energized to close the line circuit at station 1 through` relay IR and an impedance IM. Relay IR then becomes energized, picking up relay IB I a and deenergizing relay IBI. The time characteristics of the relays at each station are similar to those of the corresponding relays yat the oflice, and it Will be seen therefore that this rst impulse of the code is a short impulse.

At the conclusion of the holding me of relay IY this relay releases to cle-energize relay IV to form the second impulse of the code. Relay IR then becomes (le-energized and picks up relay IB?. A circuit is then completed for relay IZ,

from terminal I,\,through front contact' @il oi relay IKa., back vContact Sl" of relay IBM, iront contactrl of relay ICI, front contact E9 ofV relay ICI, front contact H30 of relay IBZyjumper IDI,

front contact HB2 of relay IJ, 'iront contact Hi8 oi relay I X, and Winding of relay lZ 'to terminal Iy. Relay IZ, therefore, becomes energized andl y holds relay IX energized over iront contact IES of relay'` IZ. Relay IV is therefore held deenergized. At the conclusion oi the holding interval of relay IJ, this relay releases, thereby opening front contact IUZ thereon and interrupting the circuit just traced `for relay IZ. interval, relay IZ releases, cle-energizing relay IX'. After another time interval, relay IX. releasesy After a time to energize relay IV and conclude the secondf impulse. It Will be seen, therefore,that the second impulse of the code is a long impulse. n The repeatedoperation of relays EX and IY, thereafter continues, transmittingshort impulses to the line circuit'until the 5th impulse has been initiated. At'this time, relay IBii is energized4 and a circuit is completed for relay IZ fromterminal Irr, over front. contactilt of relay IKc,

back contact ill offrelay IBa, front contact 9310i relay ICI, front contact t@ of relay iCLiront contact IE5 of relay lll-35,l jumper EN, iront contact IG? of relay EJ, front contact "lati of relay IX, and Winding of relay IZ to terminal Iy. Relay iX is thereforeheld energized to prolong the 5th impulse. releases, thereby interrupting the circuit for relay IZ, which releases to cle-energize relay 5X to piclt up relay IV. It will be seen that the l5th impulse is a long impulseuand the 6th, 7th, and Sth im- It should he noted that the pulses are short. de-energization of track .relay ITE, ywhich set the code transmitter into operation, opens contact ii andthus de-energizes relay ILAH. vThis opens contact 2li to put signal ILA to stop, so that for relay IZ is then closed from terminal Ix,

through back contact M5 of rela-y ETR, the lower winding of relay ITD,` contact MEI) of relay l-BLZ', contact ISI ofrelay ICZ, contact I62 of relayIJ,

Contact I58 of relay IX, and Winclingof relay IZ The 9th After a time interval, relay IJ.L

to terminal Iy, to pick 11p relay IZ `to prolong v the 10th impulse. comes energized in thereverse direction to close reverse contact Ml, thereby preparing a circuit to start the transmitter when. track relay ITR again picks up.

During the littL impulse, a Circuitfor relay sz` v is closed from terminal Il', over contact It-IGM,

closed when switch 3 is normal, thence throughV upper winding of relay Il/VD, front contact It@ of relay IBS, frontcontact II oifrelay ICE?, front contact |62 of relay IJ, front contact Ii of relay I Z, and Winding of relay IZ to terminal Iy. Current in this circuit picks up relay IZ to prolong the 11th impulse, and ovvs through relay IWDin such direction as to tend to move contact IE6 to Furthermore relay ITD loe-- the left. The 12th and 13th impulses are short.v

During the 'l4th impulse,- a circut yfor relay IZ is closed from terminal Im, through back contact I85.'of relay ILAH, back contactv |86 -ofrelay ILBI-I, back contact |81 of relay IRAI-I, back con-,-`

tact |88 of relay IRBH, lower winding of relay IHD, front contact 288 f relay IE5, front contact IGI of relay ICZ, front contactv I52-of relay IJ, front contact |58 of relay IX, and winding of relay IZ to terminal Iy. Current in this circuit picks up relay IZ to prolong the 14th impulse, and flows through the lower winding of relay IHD in such direction as to close right-hand contact |89. This prepares a circuit to start the'transmitter when any one of the four signal relays.

' impulse, the circuit for relay IZ is from terminal v No. 1.

Ix, over frontcontact 96 of relay IKa, front 'contact 95 of relay IK, back contact 94 of relay IE, front contact v.II of relay IT, upper winding of relay-IH, front contact |63 of relayv IB8,`front contact IGI of relay IC2, front contact |92` of relay IJ, front contact |58 of relay IX',rand winding of relay IZ to terminal.l Iy. As a result of the Vcurrent supplied.4 to thisucircuit, relay vI-Z'is held energized to prolong the 16th and last im- -grelay- OGI, and winding of relay OSI to terminal' Oy. Relay OSI then becomes energized pulse of'the code. Furthermore, the current in thel circuit just traced energizesvrelayI-H inits normaldirection, thereby opening reverse contact |58. the stick circuit for master relay IT,l but since relay IZ is now energizecl'a branch is closed around contact |50 of relay IH, through' front IT therefore IH has been When relay -IJ releases, relay IZ becomes de-energized and after a time interval, this raly opens its front contact and after `a, further itimel interval,l this relay releases to stop the transmission, closing its back Contact |52 to restore thefline circuit and com#v l plete the last impulse ofthe code, following which relays IKa and IK become cle-energized to restore the apparatus vto normal. j

It-will be seen from the foregoing .that the code transmitted'to the linecircuit `from a sta; tion consists of 16 impulses similar -to those transmitted `from the cnice, except lthat the first impulse of the code transmitted 'fromy a station to the oflice is a short impulse while the code transmitted from the cnice to the-station has In the particular code described, the long impuls-es are the 2nd, 5th, 10th, 11th, 14th, `and 16th. The code transmitted to the lineby the apparatus at station No. 1 operates ythe apparatus at the oilice in the following manner:

Line relay OR at the oilice is, of course, ener gized when the line circuit is closed, but is de-` energized during each impulse, or open circuit' interval of .the code transmitted from^station the `counting relays OBI, OBIa, etc.,y consecutively in the manner previously described. The first time relay OR becomes de-energized, relays OBI OCI, OKa, and OK become energized. This first impulse is short, but during this impulse, relay vOE (Fig. l) is energized, over a circuit which passes from terminal Ox, over back con- .i ltact 25 of relay OR (Fig. 2) back contact 26 of relay OKQI.,l iront contact 5610i relay OCI, front contact 51 of relay OBI, and winding or' relay OE to terminal Oy. When relay OEpicks up, it sticks up over its own frontcontact 60, back contact 59 of relay OLI, back contact 5,8

The opening of this contact interrupts Th master relay I-'I' is then cle-energized This operation of relay OR energizes of relay-OL2,'front contact` 54 of relayOK, andl front .contact 32 of relay OKa. During the second impulse, relay OB2 is energized and since this impulse is long, relay OJ releases, and cur` rentr then flows from terminal Ox, over back contact 35 of relay OJ, front contact 14 of relay `OC,|,'; front contact 15 of relay OE, iront contact 16 of relay OB2, and winding of relay OGI to terminal Oy. Relay OGI then picks up, and

-current ows-'over the vcircuit just traced for this relay as far as front contact 16 of `relay OB2, and thence over front contact 18 of relay OGI, and winding ofrelay' OLI to terminal Oy.

1 `RelayOLI therefore picks up, breaking the stick circuit for relay'OE and allowing relay OE to release, but relays OGI yand OLI stick up over their own front contacts, back contact 58 of relay l OL2, front contact 54 of relay OK and front contact32 of relay OKa. The third and fourth irnpulses are short, but when the 5th impulse is received, vrelay OB5v-is energized, and since this impulse is long, relay OJv releases, and current flows noni-terminal Ox, over back contact 35 ofI relay OJ, front contact 14 of relay OCI, front contact 82 of relay 0135, front Contact 83 of and OGI drop, and completing a stick circuit for relay OL2 `over its own front contact 58, front Contact 54 of relay'OK, and front contactf32 of relay OKa. Relay OSI is also stuck up over a ycircuit including itsj own front contact 84,

front contact 58 of relay OL2, frontcontact 54 ofV relay OK, and front contactS? of yrelay OKa. TheI circuits for relays OLI, OL2, OGI, and OSI' are similar tothe circuits previously detransmission of f a-cod'e from the ofce and .will be readily understood without tracing these circuits in--further detail. The next long impulse in the code is the 10th impulse and when this impulse is received, relay OBZ is energized. During thisimpulse, relay OJ releases, `and since lrelayOCZ is now picked up', current flows from yterminal 0.1,'through back' contact 35 of relay OJ back Acontact |96 of relay OT, front contact |91Vofr`elay"OC2, contact |10 of relay CB2, and `winding of relay OFZ to terminal Oy. As a result, relay OF2 picks up and sticks over its own iront contact I1I, front contact 54 of relay OK and front contact'32 of relay OKa.

During the 11th impulse, which is long, relay OF3 picks-up over front contact"v |98 of relay OB3, and sticks over its own front contact |99. The'12thandf13th impulses are short so that relays O-F4 and OF5 vdo not pick up.

During` the 14th impulse, which is long, relay OF6` picks up over front contact 229 of relay OBS,l and sticks over its own front contact 230. .The th impulse is short so that relay CF1 does not pick up. During the 16th impulse, which is long, the operating circuit is closed from terminal Om, -back contact 35of relay OJ, back contact |96 of relay OT, front contact |91 of relay 002, iront contact |12 of relay OB8, andfrom .thispoint one branch is completed over front contact |13 of relay OF2, winding of relay ITK, -front contact |14 of relay OSI. and back contact-|15 of relay OFI to .terminal Oy. Curscribed for these relays in connection with the `rent over this branch reverses relay ITK, closfront contact ISI of relay OFS, winding of relay OHKI, contact |92 of relay OSI, back contact |93 of relay OF5 and back contact 20| of relay OFT to terminal Oy. Current over this branch causes contact |35 of relay'OI-IKI to move to the right to open the circuit for lamps |21 and |28 and to close the circuit for lamp |29, thus light.I ing lamp |29 to indicate that the signals are at Stop'u I When the code signal is completed, relays OR and vOJ pick up and remain energized, and all other relays become de-energized, restoring' the apparatus to normal. On panel No. 1, lamps I'EI, IBI, and |29 will now remain' lighted until a new code signal is received from station No. 1.

Returning now to station No. 1, We will assume that the train moves out of section a-b, so that track relay ITR picks up. The closing of front contact 3 of this relay picks up relay ILAH to again clear the signal ILA. A starting circuit yis novvV closed from terminal I over front contact MI5 of relay ITR, reverse contact 41 of relay ITD, back contact M8 of relay IT and lower Winding of relay IH toterminal Iy'. The starting relay IH is therefore energized in the reverse direction and the equipment at station No. 1 is actuated to transmit a code to the line 'circuit in a manner similar to that already'dei scribed in connection with the operation of the apparatus in response to the entrance of a train into section a-b, with the difference, however', that the 9th, 11th, and 13th will belong impulses instead of the 10th, 11th, and 14th. During the 9th impulse of this code, relays IBI and |C2 are energized and a circuit for relay IZ is then closed from terminal Ix, over fro-nt contact |46 of relay ITR, the upper Winding of relay ITD, front contact IIirl of relay IBI, front contact IIiI of relay; ICE, front Contact |82 of relay IJ, front Contact |53 of relay IX, and winding of relay IZ, to terminal Iy. Relay IZ therefore picks up to prolong the 9th impulse, and relay ITD is energizedlso as to move contact |47 to the left.v The 10th impulse will be short, the 11th impulse will .be long, as already described, and the 12th impulse will be short. During the 13th impulse, a circuit for relay IZ is closed from terminal Ir, through contact Zilli-2920i closed when switch 3 is normal, back contact 2M of relay IRAH, front con tact 283 of relay ILAI-I, to wire ZII);A From this point one branch continues through 'upperV winding of relay IFD, front Contact 2I5 of relay IE5, f

the 13th impulse, and ows through the upper Winding of relay IFD tending to move contact 235 to the left, but under the assumed condi-v tions this contact is already in that position.

This preparesa circuit to start the transmitter if the traffic direction is reversed to pick up r'e i v'sticks over its oWn contact 228.

' IWS is noWin disagreementjwith the switch lay IRAH or relay IRBH. A secondV branchr'oi the circuit extends from Wire 2|@ through front contact 2| of relay IE5, and the upper winding of relayy II-lD to terminal I y. Current in this branch 'causes contact |89 of relay IHD to move to the left, to prepare a circuit to start the transmitter when all the signal relays become de-energized.

The 14th and 15th impulses are short, and the operation during the 16th impulse is as already described. In the code just described therefore,

the long impulses will be the 2nd, 5th, 9th, 11th,v'

13th, and 16th.

The voperation of the oice equipment in` re-y I sponse to the code just described for an uncccupied track section is similar to the operationv in receiving anindication of an occupied track sec-Ql v tion, except that the 9th, 11th, and 13th Will be` long impulses instead of the 10th, 11th, and 14th impulses.l During the 9th impulse, relay OFI picks up over front contact I YB of relay OBI, and sticks over its own front contact y I'Il. The

10th impulseis short so that relay OF2 .does not L pick up. During the 11th impulse relay OFS picks up andsticks as already described, and. the 12th impulse is short so that lrelay OFII does not pickup. During the 13th impulse, relay OF5. picks up over front contact 2I'I of relay OBS, and The 14th and 15th impulses are short so that relays 0F61 and OFI do notpick up. Y

During the 16th impulse, the operating circuit is closed from terminal Ox over contacts 35, ISIS,

|91, |72 as already described, one branch cone" tinuing over front contact I'IE of relay OFI, contact I'IAI of relay OSI, winding of relay lTK, and

back Contact |13 of relay OFE vto terminal Oy. Current over this branch restores relay ITK tov normal, opening contact II to extinguish lamp ITI and thereby indicating track unoccupied.

The second branch of the operating circuit energizes relay IWK to the left, as already described, to insure that lampy ISI is lighted, and a third branch is completed over front contact 93 i of'relayOFE, front contact |92 of relay OSI, Windf ing of relay OHKI, back contact IGI of relay OFS to terminal'Oy. Current over thisb-ranch energizes relay O'I-IKI to move Contact |35 to the left. A fourth branch of the operating circuit is coinpleted over front contact 2M of relay OF5, frontk contact ZI?. of relay OSI, Winding of relay OFKI, and back contact ZIZof relay OFT tov terminal.' Oy. Current ,over this branch energizes relay OFKI tending to move Contact ISA to thelleftpv but this contactwas assumed to be in that position 'I-husv lamp |29 is extinguished and lamp Y |21 lighted to indicate that an eastbound signal is cleanand since lamp ISI is lighted showing that the switch isnormal, this is knowny to be signal ILA and.- not ILB. i

I Will neXt assume that the operator reverses'y lever Id to reverseswitch S. It has been shown that the lcode signal in response to this movement results at station No. 1 in moving Contact 9 of relay IWS from left'to right, but contacts II and I3 of relays IHS and yIFS will remain closed to the left. This opens the circuit of etL signal relay ILAH at contact 9, because relayirl position, andsignal ILA is put to stop.' IOne result ofthis operation is to cause the transmission to the oice 'of a return indication code indicating ythis change of conditions at the station. A second result is to close back contact I0, theresy by completing the .circuitl to reverse switch` 3.

Whenswtch 3 is reversed and locked, one re.- sult istofclose' a transmitter starting circuit from tact |66 of relay IWD, back contact |69 of relay IT and lower winding of `relay IH. Contact then closes to start the transmitter in the manner tact I8 of relay IFS, contact I9-|9b, and winding of relay ILBH, which thus picks up to clear signal ILB. This return indication `code signal will therefore have its 9th `impulse long, the cir cuit for. relay IZ being closed from terminal Ir, over front contact |46 of kyrelay |TR and contact f |64 of relay IBI, as described hereinbefore. The

sis

10th and 11th impulseswill be short, but the v12th will be long, the circuit for relay IZ being closed from terminal Ix, over contact IE5-40519, lower winding of IWD, front contact |61 of relay IBII, frontfcontact |6| of relay IC2, front contact |62 of relay IJ, front contact I58of relay Ix,

and winding of relay IZto terminal Iy'. When v'the 12th impulse is transmitted, current in this circuit will energize relay `IVVD to move kContact |86 to the' left, thus opening the starting circuit 'Ito-prevent repetition of the code. Since signal ILBI-I` is now clear, the 13th impulse will be long and the 14th and 15th impulses will be short. The circuit for IZ to prolong the 13th impulse is fromy terminal Izr, over contact 202'-202b, back' contact'208 of relay IRBH, front contact 201 of relay ILBH, wire 2| 9, upper winding of IFD, contact 2|5 of relay v|B5,andthence through contacts |6|,' |62, and |58 tjo relay IZ. Current in this circuit tends to move contact 205 of relay IFD toA theleft, to prepare a starting circuit in case traflic direction is reversed; The circuit just traced is provided with a branch which passes from wire 2 I 9, through front contact 2 I6 of relay las, Contact 221 of relay lcz, upper winding of relay IHD to terminal Iy tomove contact |89 to the left, provided it had been moved to the right by a preceding code transmission.v This prepares a starting circuit available in the event 'that signal ILB goes to. stop. This code is completed by a 16th long impulse in the usual manner.v

When the last mentioned codeis received at the office, since the 9th, 12th, and 13th impulses are long, relays OFI, GF4, and OF5 will be picked up. The pick up circuit for relay GF4 is similar ,to the corresponding circuit for relays OFI and OF5 previously described and yincludes front contact |80 of relay OBII. Relay OFII sticks up over its own contact 228.

During'the 16th impulse the operating circuit is closed from terminal Ox, over contacts 35, I96, I91, I12,one branch energizing relay ITK as already described, and a second branch being closed over front contact |82 of relay OF4, winding of relay IWK, contact |83 of relay OSI, back Contact |84 of relay OF3 to terminal Oy. Current in this branch reverses relay IWK to close right-hand Contact |33, and since relay OWDI has been reversed in transmitting the control code from the office, this completes .a circuit to light reverse switch indication lamp |32 over contacts |33 and |30. Relays OHKI and O-FKI are also energized to the left as inl a previously described code, t0 light lamp |21,

thereby showing that an eastbound signal is clear, and'since lamp |32 is lighted, this is' known l to be signal ILB and not signal ILA.

"I will next` assume that the operator returns f lever Id'to normal, and transmitsa code to station No. 1 to restore switch 3`to normal. yThis code will have its '1st, 2nd, 5th, 11th, 13th, and

16th impulses long and yhas already been described. 'Ihe previous code resulted in the reversal of relay '|WD, andtherefore when switch 3 is restored to normal, 'a starting circuit is completed from terminal Ir, overcontact |65I.65a, reve-rse contact |68 of relay IWD, back contact |09 of relay IT, and the lower winding of relay IH, to start the transmission 'of a return indication code which will be the same as that prevlously'descrlbed as the result of a train leaving section zzn-b, the long impulses in this code being' the2nd, 5th, 9th, 11th, 13th, and 16th.'l

At the oice, this code restores relay IWK to normal, and since relay OWDI has been restored to normal by the control code impulse sent out, normal indication lamp |3I will be lighted.

It has been shown that the operation of the switch involves the transmission of two return indication codes,=rst that the signal has been put to stop, and second, that the switch has com` pleted its movement and the signal has cleared,

However, in`

or is at stop, as the case may be. case the line is busy or occupied by the transmission of other code during the 20 or 30 seconds usually required for the switch to operate, and all operations are completed at the station before the line is available, it is evident that but a single return code will be transmitted, ythus economizing in the use of the line.

I will now assume that the operator has sent.

a codel to put the signals at station No.` 1 at stop by reversing relay IHS to open contact I1. 'This closes a starting circuit from terminal In: over back contacts |85, |86, |31, and |88`of the four signal relays, left-hand contact |89 of relay'IHD, back contact |90 of relay IT, and the lowerwindnsy ing of relay IH, to terminal Iy. `Relay IH then reverses to start the transmission of a code from ,station No. 1, in which code the 2nd, 5th, 9th, 11th, 14th, and 16th impulses will be long. When the 14th impulse of this code is transmitted, a circuit is closed for relay IZ from terminal Ix, 'over back contacts |85, |86, |81, and |88 of the signal relays, through the lower winding of relay II-ID, front contact 200 of relay IBB, contacts ISI, |62, and |58, andwinding of relay IZ to terminal Iy. Relay IZ is then'held up to prolong the 14th impulse, and relay IHD is energized in the reverse direction to close its right-hand contact |89, thereby preparing a starting circuit available when anyone of the four signal relays becomes energized.

At the oice, the 14th impulse of this code will pick up relay OFS over contact 229 of relay OBS, and' this relay will stick up over its own contact 230, the remainder 0f the selection being as previously described so that relays OFI,` and OF3 are also picked up. During the 16th impulse one branch of the operating circuit' is closed from lterminal Ox, over backcontact 35 of relay OJ,

'tacts |93,r and back contact 20| of relayO-FLto terminal Oy. Relay OHKI is thereby reversed to close right-hand contact |35. Lamp |29 then is lighted to indicate to the operator that'all of vthesignals at station No;

` IRAH becomes energized. A starting circuit is then closed from terminal Ix, over contact 2ER-2mn, back contact 233 of relay ILAI-I, -front s contact 294 of relay IRAH, wire 2 I3, normalcontact 2Il5 of relay IFD, back contact 2&6 of relay IT, and the lower winding of relay IH to terminal Iy. Had switch 3 been reversed, relay IRBI-I would have been energized and the starting circuit would have been closed over contact EQ2- 20212, back contact' 2N of relay ILBI-I, front Contact 298 of relay IRBH, to wire 2I8. In case the last preceding` clear signal had been a westbound signal, relay IFD would have been reversed and the above starting circuit-would be open at left-hand contact 295. In this case the transmission is started over a circuit that is completed from terminal Ix, through contact |85 of relay ILAH to right hand contact |89 of relay IHD and, contact I9@ of relay IT. This circuit is closed if the preceding transmission included the indication of a stop signal. `The transmission of the code indicating that a westbound signal is clear opens both the aforesaid starting circuits to prevent repetition. This is accomplished by reversing `relay IFD by current in the circuit from wire 2 I8 lower winding of relay IFD, and contact 2H) of relay IB'I and thence through relay IZ to terminal Iy, and by restoring relay IHD to normal yby current in the circuit from wire 2I8, contact 209 of relay IBI, contact 221 of relay IC2, upper winding of relay IHD to terminal Iy. This return indication code will have long 2nd, 5th, 9th, 11th, 15th, and 16th impulses. At the oice the 15th impulse will pick up relay OF'I over contact 2II of relay OB'I, and relay OF'I sticks up over its own contact 23|. Relays OFI and OF3 are also energized as previously described. During the 16th or operating impulse a branch will be closed for the operating circuit from front contact 2|2 of relay OFI' through the winding ofrelay OFKI, front contact 2I3 of relay OSI, back contact 2|@ of relay OF5 to terminal Oy, and a second branch circuit will be closed from front contact 29| of relay OFT, through back contact |93 of relay OF5, front contact |92 of relay OSI, 'winding of relay OHKI, and backcontact ISI of relay OF5 to terminal Oy. Current through these two branch circuits causes contact `of relay OHKI to move to the left and contact ISAv of relay OFKI to move to the right, and since contact |22 of relay OFDI occupies the right hand position as the result of transmission of the preceding operating code, the circuit'of lamp I 28 is closed to light lamp I 28 and indicate that a westbound signal is clear. Since normal switch indication lamp I3I is also lighted, this is known to be signal IRA and not IRB. I will now assume that the operator wishes to change the set-up at station No. 1 from an eastbound main line move as shown in Fig. 3 to a westbound move from the siding toA the main line. He then reverses both levers Id and I f and operates push button OPI, and sends a code having -the- 1st, 2nd, .5th, 12th,.15th, andv 16th impulseslong.`

@197,130 At station No; l, this codenot only causes the reversalv of` relay IWS, which puts signal k ILPL at stop and reverses the switch, 'but also causes relay IFS toreverse, so that when the signal circuit is closed at the completion of the op.- eration of the switch, signal IRB clears insteady of ILA. This causes the transmission of a return indication code whose long impulses are the 2nd, 5th, 9th, 12th, 15th, and 16th to operate the correspondingindication relays of panel No. l, and light lamps E32 and |28, thereby indivcating that vthe switch has been reversed and the westbound signal cleared. s I will next assume that a train is making the move last provided for, that is, moving west from the siding tothe main track, and that the operator wishes to prepare the route for an approaching west bound train, but to hold the latter train at station No. l. VThe entrance., of the rst train into section a-b, has of course caused the transmission of a return code indi-` cating track occupied, switch reversed, and signal at stop, the signal, however being in` condition` to clear as soon as the train passes point a. The v operator now restores lever Id to normal and'v moves lever If to the middle position, and op-` crates pushbutton OPI 'to send a code whose long impulses are the 1st,'2ncl, 5th, llth, l14th, and

16th. This'cod'e, at station No. l, causes contact 9 of relay IWS to move to the left, and contact Il of relay' IHS to move to the right. -AsV soon as the rst train passes point d, track relay ITR picks up to energize relay .Ik and cause switch 3 to be restored to normal, but the clearing vof the signal is now prevented by the open contact I7, -so that the following train will be held at signal IRA. The long impulses'of vthe return f indication Code` in this case will be the 2nd. 5th.'

9th, 11th, 14th, and 16th, which code has'alrealkrly` -I been described. v

It is evident that there are 6 different codes that can be transmitted from the oice to each station; one for each of the three positions of signal lever If, with switch lever Id normal, and fj one for each of the three positions of signal lever If with switch lever I d reversed, so that every possible train movement at a station can be con- L trolled by the transmission of a single code signal I to the station. It is also plain that a return indication of every possible combination of conditions at the remote station can be accomplished with a single code signal. f

One important feature of my invention is Ythe use of a single composite code signal to operate all the functions at a selected one of a pluralityy of stations, or to transmit indications of a plurality of functions from remote stations to a central oihce by means of a single composite code signal as herein described.

The advantages of the use of a composite codel as herein described are threefold; the prime-adcircuit is thereby accomplished. In controlling several functions at a station, (in this case, a switch and two opposing signals) the operator is required to send but a single code to perform any or all the operations that he may need to a'ccom-4 plish at one time, without repeating the elements of the code sig-nal which select the particular .station. On a busy railroad, if individual codes are used for each function, it may happen: that the lineis in use constantly, and at: times considerable delay in the receiptof return indica',-

tions may result, particularly if severalaindications accumulate ateach station.- By the-,useof av composite code, the .maximum tinieyaJ kstation'can vantage is that a more eiicient use of the line 

